In Ecclesiastes 9, Solomon urges, “Go, eat your bread in happiness and drink your wine with a cheerful heart; for God has already approved your works.” Joy comes from knowing that God accepts and approves what we do, and, implicitly, accepts and approves us. God finds something in our works to delight Him. That approval brings us joy, and the joy is manifested in a cheery feast of bread and wine.
The verb “approve” is the Hebrew ratzah, used to describe Yahweh's acceptance of offerings (Leviticus 1:4), offerers (Leviticus 7:18), and human works (Deuteronomy 33:11). Yahweh approved David as king over Israel (1 Chronicles 28:4), and several Psalms include pleas for Yahweh to approve and deliver David (40:13; 119:108; 147:11; 149:4).
The word implies delight and pleasure. It doesn't have the same judicial connotation as terms like “judge” or “justify,” but it does imply an informal act of valuation and judgment. God “approves” whomever or whatever is pleasant and delightful in His sight.
To put it in Christian terms: We are approved by God in Christ, and our works are fruits of His Spirit. Justified in Christ, we stand under God's approving eye. Because He rejoices over us, we rejoice before Him. Our feast of bread and wine is a festive declaration of our being-approved. The fact that we feast with joy expresses our confidence that we are justified. To share in the joy of the feast is to share in God's approval.
As N.T. Wright said in one of his earliest essays, the message of the doctrine of justification by grace through faith is: Relax. To which we may add: Rejoice.
(This post was inspired by a sermon by Rev. Rich Lusk, November 20, 2016.)